Cylinder paper machine



July 15, 19438 P. H. GOLDSMITH 2,249,123

CYLINDER PAPER MACHINE Filed Dec. 23, 1957- INVENTOR Philip H.ljoldsmiih BY amflm ATTORNE S overflow type of vat.

Patented July 15, 1941 CYLINDER PAPER MACHINE Philip HQGoldsmith,Hamilton, Ohio Application December 28, 1937, Serial No. 181,305

z Claims. This invention relates to paper making machinery and moreparticularly to cylinder paper machines of the type commonly used formanufacturing the heavier grades of paper, such as paperboard and thelike.

A cylinder paper machine consists of one or more vats, each equippedwith a foraminous rotatable cylinder mold partially immersed in aquantity of stock contained in the vat. The water from the stock passesthrough the foraminous surface of the rotating cylinder mold, and thefibers are retained on the surface to form a continuous web which isremoved near the top of the cylinder mold onto an endless felt belt. Onmulti-cylinder machines the same felt usually picks up the web fromseveral cylinder molds to form a composite sheet. Since it is frequentlydesirable to make the different plies of the'sheet of diiferentmaterials and diflerent thicknesses, each vat is-ordinarily equippedwith its own stock supply system and is really a separate machine.

The physical characteristics of the web are largely determined by therate at which stock flows past the surface of the cylinder and by thedirection of flow of stock relative to the surface of the cylinder. Forrelatively light-papers, it is usually desirable to supply stock to thevat at such a rate that considerable quantities may be removed at apoint beyond the cylinder and recirculated. For relatively heavy papers,on the other hand, it is thought desirable to operate withoutrecirculation of stock.

There are many types of vats known in the art, each suitable for aparticular grade of board under individual conditions 01 speed, natureof raw material, and requirements of product. The two types of vat mostwidely used heretofore, may be referred to for the purposes of this de-'scription as the counterflow type of vat and the In the counterflow vatstock is fed to the upturning side of the cylinder mold and flows in adirection contrary to the direction of rotation of the cylinder mold.Such a vat normally operates without recirculation of stock. In theoverflow type of vat, the stock is supplied to the downturning side ofthe cylinder mold and flows in the same direction as the surface of themold. In vats of this type, a portion of the stock is removed at a pointbeyond the cylinder and recirculated.

In many cases, particularly where a mill makes such products as thenumerous varieties of paperboards grouped under the name boxboard, acylinder. machine is required to form a wide variety of products frommany different types of stock. Such a machine might, for example, berequired to form a sheetas light as .009 of an inch thick in finisheddry caliper, and also a sheet. as heavy as .063 of an inch thick infinished dry caliper. At times it may be necessary to handle as manyas-four different stocks on different vats of the same machine at thesame time. Different piles of the same sheet, each made in its own vat,must often have widely different characteristics, and cylinder moldspeeds must be varied widely to make a variety of products. It is knownby those conversant with the art that the various factors affecting webformation must be adjusted properly for each different set ofconditions, and that it is not possible to do this within wide enoughlimits with the machines which have been developed heretofore.

The following illustrative example is given to point out a type oflimitation to which machines of the priorart'are subject:

Suppose-that a vat of the overflow type is designed for a normal flo'wthrough the mold 'of 1500 gallons per minute with a particular type ofstock, and an overflow of 500 gallons per minute. The thickness'of thesheet formed is inversely proportional to the peripheral speed oi. thecylinder mold and for best operating conditions it is desirable that therate of flow of stock be about one-half the peripheral speed of themold. Hence, if the speed of the mold is doubled to make a sheetone-half as thick, it will be necessary to supply 4000 gallons perminute of stock instead of 2000 gallons per minute. Since the flowthrough the mold is substantially independent of the speed of rotationof the mold, approximately 2500 gallons per minute ofoverflow would berecirculated under these" conditions. As indicated above, it issometimes desirable to produce sheets having a sevenfold variation inthickness. Such a sevenfold variationin sheet thickness would require asevenfold variation in peripheral speed of the cylinder mold and atwenty-five fold change in the quantity of stock recirculated. It isapparent that practical problems of structural design and the large costof power involved, make it highly undesirable to handle such largequantities of stock. Since the overflow vat is admirably. suited toproduce the lighter weights of paper, it is usually desirable to usesuch a vat in making sheets up to, say, .030 of an inch, and to use acounterflow vat for forming extremely heavy grades. The counterflow vathas long been used to form relatively heavy sheets at relativelyglowspeeds, and does not produce a good sheet athigh speeds.

It is an object of this invention to provide a cylinder paper machinehaving a high degree of operative flexibility, so that the operator mayselect the particular type of flow best suited to produce the particulargrade of paper he is making. The machine of the present invention isadapted to use any of the four following methods of flow:

1. The overflow method as described above;

2. The counterfiow method as described above;

3. Flow against the cylinder (1. e. supplying stock to the upturningside of the cylinder) with recirculation of a portion of the stock; and

4. Flow from both sides of the cylinder. I

Machines adapted to use the above methods of how individually are wellknown in the art. U. S. Patent No. 2,059,184 to Kutter discloses atypical machine adapted to use method No. 1. And U. S. Patent No.2,036,168 to Gibson and Engert discloses a typical machine adapted touse method No. 4. But method No. 4 cannot be used with the Kuttermachine, nor can method No. 1 v

be used with the Engert and Gibson machine. Since an average cylindermachine produces one hundred tons or more of finished board per day,most mills operate only one or two machines. In order to take advantageof certain economies in the cutting operation, it is desirable where twomachines are used that they be of different vention makes possible atwo-machine installation wherein the machines have different trims, andwherein each machine can produce a wide variety of papers at optimumoperating conditions.

The many other objects and advantages of the present invention may bestbe appreciated by reference to the accompanying drawing, which showssomewhat schematically one embodiment of the invention. Referring to thedrawing:

A rotatable cylinder I having a foraminous surface 2 is partiallyimmersed in a quantity of stock contained in a vat generally indicatedat 4. A partition 5, commonly called a vat circle, forms within the vat4 a hemi-cylindrical chamber in which the rotatable cylinder issuspended in such a way as to form a passage 6, commonly called the vatcircle space, through which stock may flow. Suitable seals at the end ofthe cylinder prevent stock from flowing into the interior thereof. Asthe cylinder rotates, water from the stock, commonly called whitewater,passes through the foraminous surface 2, leaving a web of fiberdeposited thereon, flows from the ends of the cylinder into a pair ofcompartments, not shown, and leaves the vat through pipe line 3. Spillsare provided in each compartment to remove excess whitewater from thesystem. The web of fiber formed on the surface of cylinder I is removednear the top of the cylinder, and is caused to adhere to the under sideof an endless belt 34, by the use of a couch roll 35.

Stock is supplied to the vat 4 through a main underfeed supply pipe 36,and may pass to the vat circle space 6 in any of three ways. If valve 1is open and valve 9 is closed, the stock will flow into a conduit 8,comprising a lower portion 31 called the vat hopper, and an upperportion 38 referred to as the vat inlet pass. Thence, the stock flowsover a shoulder 39 commonly called the making board to the vat circlespace 6. If the valve 9 is open and the valve I shut. stock will flowthrough the hopper 40 and inlet pass 4| of the conduit l0, over themaking board 42 and thence into the vat circle space 6. If valves 1 and9 are both open, stock will flow to the vat circle space 6 through bothconduit 8 and conduit l0.

The level of stock over the making boards 39 and 42 is controlled inpart by a pair of adjustable dams 24 and 25. The dam 24 is supported bya pair of threaded shafts 25, only one of which -is shown, and may beraised or lowered by rotation of a pair of hand wheels 28, only one ofwhich is shown. The dam 25 is supported in a similar manner by the shaft21 and may be similarly raised or lowered by rotation of hand wheels 29.The dams 24 and 25 are held against the upper extremities of the vatcircle by suitable guides 3| and 32 at the vat ends.

Overflow stock may leave the vat either through conduit 8, valve l2 andpipe line l5, or through conduit l0, valve l3 and pipe line H. Pipes l4and I5 converge to form a pump suction line I6 of the circulating pumpH. The circulating pump I'I returns overflow stock and some of thewhitewater through a pipe line I9 to the headbox I9 which communicateswith the feed pipe 36. Fresh stock is admitted to pipe line 29 and flowsthrough line 2|, where it is diluted by the proper amount of whitewater,to a screen 22, thence through pipe 23 to headbox l9, where it is mixedwith the recirculated stock before passing into the main supply line 36.Enough whitewater is drawn by whitewater pump 44 to dilute the freshstock coming to the screen 22 through pipe 2| as described. Theremainder of the whitewater passes through pipe 45, pump suction linel6, and is mixed with the overflow stock in circulating pump H.

The operation of the vat is as follows:

When it is desired to flow in the overflow manner as described above,valves 1 and I3 are opened and valves 9 and I2 are closed. Stock thenflows through the conduit 8 to the vat circle space 6. A portion of thestock is overflowed over dam 25 and returned to the circulating pump I1through conduit l0 and pipes l4 and Hi. When it is desired to operate incounterflow manner as described above, valve 9 would be opened, andvalves 1, l2 and I3 would be closed. Under these conditions, the dam 24would be raised to its uppermost position, as no overflow isrecirculated when using this method. Stock would flow through conduit l9and over making board 42 to the vat circle space 6. When it is desiredto operate with method No. 3 described above, valves 9 and I2 would beopened, and valves I and I3 would'be closed. Under these conditionsstock would flow in through the conduit l0 and over the making board 42to the vat circle space 6. A portion of the stock would pass over thedam 24 through conduit 8 and pipe lines l5 and I6 to circulating pumpll. When it is desired to operate according to method No. 4, describedabove, valves l2 and I3 would be closed and valves 1 and 9 opened. Underthese circumstances, stock would flow through both conduit 8 and conduitIn, over making boards 39 and 42 to the vat circle space 6.

From the above description, it should be apparent that the machine ofthe present invention makes possible the use of any of the four methods1 of fiow outlined above, and that it may be converted from onemethod-oi operation counterflow manner or with an overflow atwill,

depending on the product he wishes to make,its weight, the origin,treatment and freeness of the stock, the speed of the machine, etc.machine eliminates wasteful duplication of production equipment and maybe used as onevat of a multi-cylinder machine to produce'papers havingwidely different characteristics.

Since many embodiments might be made of the above invention, and sincemany changes might be made in the embodiment above described, it is tobe understood that all matter hereinbefore set forth or shown in theaccompanying drawing is interpreted as illustrative only and not in alimiting sense.

I claim:

1. Ina cylinder paper machine of the type wherein a foraminous rotatablecylinder is suspended in a vat to form a vat circle space which issupplied with a paper stock from a headbox and wherein stock in passingfrom said headbox Such a line, a second branch conduit connecting saidvat circle space at the upturning side of 1 said cylinder with said mainsupply line and said .pump suction line, and valve means in said secondbranch conduit for selectively causing stock to flow through saidconduiteither from said main supply line to said vat circle space orfrom said vat circle space to said pump suction line.

2. In a cylinder paper machine of the type wherein a foraminousrotatable cylinder is suspended in a vat to'form a vat circle spacewhich is supplied with a paper stock from a headbox and wherein stock inpassing from said headbox to said vat passes through a main supply lineand recirculating stock in leaving said vat passes through a pumpsuction line, the combination of a branch conduit connecting said vatcircle space at the downturning side of said cylinder with said mainsupply lineand said pump-suction line, a pair of valves located in saidbranch conduit for selectively causing stock to flow through saidconduit either from 'said supply line to said vat circle space or fromsaid vat circle space to said pump suction line, a second branch conduitconnecting said vat circle space at the upturning side of saidcylinderwith said main supply line and said pump suction line, and apair of valves located in said second branch conduit for, selectivelycausing stock to flow through said conduit either from said main supplyline to said vat circle space or from said vat circle space to said pumpsuction line.

PHILIP H. GOLDSMITH.

